Left Atrial Function Is Improved in Short-Term Follow-Up after Catheter Ablation of Outflow Tract Premature Ventricular Complexes

Mechanisms and Risk Factors for Premature Ventricular Contraction Induced Cardiomyopathy

Frequent premature ventricular contractions (PVCs) can cause a reversible form of cardiomyopathy in patients without structural heart disease. Because of the challenging nature of PVC-induced cardiomyopathy (PVICM), the mechanisms and risk factors for PVICM are still unclear. Based on the evidence from retrospective and observational studies, the risk factors for the development of PVICM, in addition to PVC exposure, include QRS duration, coupling interval and male sex. Based on animal models, abnormal calcium handling and cardiac remodeling may be the crucial mechanism underlying the development of cardiomyopathy. We have summarized the current knowledge on PVICM in this review. Understanding these mechanisms and risk factors is important for the diagnosis and management of this condition, which can lead to heart failure if left untreated.

Successful radiofrequency catheter ablation of idiopathic premature ventricular complexes originating from the outflow tract improves heart failure-related quality of life

BACKGROUND

To investigate the effect of successful RFCA in patients with idiopathic outflow tract PVCs (OT-PVC) on left heart functions, neurohormonal activation, functional status, and heart failure-related quality of life (HFQoL), with an integrated approach.

METHODS

Patients with frequent OT-PVCs, determined by 12-lead surface ECG who underwent radiofrequency catheter ablation (RFCA) with an acute success, were prospectivelly enrolled. Left heart functions were evaluated with the use of transthoracic echocardiography, neurohormonal activation with N-terminal Pro-brain natriuretic peptide (BNP), functional class with New York Heart Association (NYHA) and 6-min walking distance (6MWD), and HFQoL with Minnesota Living with Heart Failure Questionnaire (MLHFQ), at baseline and at 6 months.

RESULTS

A total of 108 patients were included in this study (43 ± 12 years old, 56% male). Majority of the OT-PVCs originated from aortic valve and right ventricle outflow tract (44% and 37%, respectively). Total RF time was 216 ± 87 s. Major complication rate was 0.9%. Left ventricle (LV) ejection fraction increased from 47 ± 8 to 53 ± 6% at 6 months (p < 0.001). Neurohormonal activation was suppressed significantly (104 ± 69 to 83 ± 42, p < 0.001). Functional class improved with %NYHA-I patients increasing from 54 to 89% (p < 0.001) and 6MWD from 293 ± 73 to 335 ± 59 m (p < 0.001). MLHFQ score improved from 32 ± 9 to 23 ± 5 p < 0.001. In multivariable analysis, LV end-systolic diameter (LVESD) and 6MWD were independent predictors of improvement in MLHFQ (for LVESD Uβ: - 0.26, 95%CI [0.44-0.09], p < 0.004 and for 6MWD: 0.04, 95%CI [0.03-0.06], p < 0.001).

CONCLUSIONS

RFCA of OT-PVCs is associated with improved well-being of patients, determined by left heart functions, neurohormonal activation, functional class, and HFQoL.

Could premature ventricular contractions lead to atrial remodeling?

BACKGROUND

Premature ventricular contraction (PVC) is a frequent kind of arrhythmia that affects around 1% of the general population. While PVC most frequently impairs ventricular function in structurally normal heart, retrograde ventriculo-atrial conduction can occur in people with PVC. These retrograde atrial activations may mimic pulmonary vein-derived atrial ectopies. As a result, PVC may raise the risk of atrial fibrillation (AF) by retrograde ventriculo-atrial conduction. The Four-Dimensional Automated Left Atrial Quantification (4D Auto LAQ) tool is a left atrial analytical approach that utilizes three-dimensional volume data to quantify the volume, as well as LA longitudinal and circumferential strains. The purpose of this study was to determine if clinical diagnosis of PVC is connected with abnormal LA function as determined by LA strain evaluation utilizing a 4D Auto LAQ compared to the healthy population.

METHODS

The 58 patients with frequent PVCs and 53 healthy volunteers as a control group were enrolled in the study. Imaging was performed using the GE Vivid E95 echocardiography equipment (GE Healthcare; Vingmed Ultrasound, Horten, Norway) equipped with an M5S probe (frequency range: 1.5-4.6 MHz) and a 4V probe (frequency range: 1.5-4.0 MHz). Images were imported into and were selected for analysis using the EchoPAC203 software (GE Healthcare). The analysis mode was selected, followed by the volume and 4D Auto LAQ submodes. Following that, the sample point was positioned in the center of the mitral orifice in each of the three planes. The review function was used to acquire the LA parameters measured by 4D Auto LAQ, including volume and strain parameters.

RESULTS

The maximum left atrial volume (LAVmax) and minimal left atrial volume (LAVmin) were significantly higher in the patient group (38.91 ± 9.72 vs. 46.31 ± 10.22, 17.75 ± 4.52 vs. 23.10 ± 7.13, respectively, all p values <.001). On the other hand left atrial reservoir longitudinal strain (LASr), conduit longitudinal strain (LAScd), contraction longitudinal strain (LASct), reservoir circumferential strain (LASr-c), conduit circumferential strain (LAScd-c), and contraction circumferential strain (LASct-c) were significantly lower in patient group (26.64 ± 5.64 vs.19.16 ± 4.58, -19.53 ± 3.72 vs. -11.28 ± 3.47, -10.34 ± 1.56 vs. -4.59 ± 1.49, 30.72 ± 4.04 vs. 19.31 ± 2.60, -19.91 ± 1.78 vs. -13.38 ± 2.85, -15.89 ± 6.37 vs. -9.24 ± 1.63, respectively, all p values <.001).

CONCLUSIONS

The present study found that premature ventricular complexes can lead to atrial remodeling as well as ventricular remodeling in patients with PVC and 4D LAQ technology can quantitatively examine left atrial function and determine these alterations early.

Mechanisms, time course and predictability of premature ventricular contractions cardiomyopathy-an update on its development and resolution

Frequent premature ventricular contractions (PVCs) associated left ventricular systolic dysfunction (LVSD) is a well-known clinical scenario and numerous predictors for cardiomyopathy (CMP) development have been already thoroughly described. It may present as a "pure" form of dissynchrony-induced cardiomyopathy or it may be an aggravating component of a multifactorial structural heart disease. However, the precise risk to develop PVC-induced CMP (which would allow for tailored-patient monitoring and/or early treatment) and the degree of CMP reversibility after PVC suppression/elimination (which may permit appropriate candidate selection for therapy) are unclear. Moreover, there is limited data regarding the time course of CMP development and resolution after arrhythmia suppression. Even less known are the other components of PVC-induced CMP, such as right ventricular (RV) and atrial myopathies. This review targets to synthetize the most recent information in this regard and bring a deeper understanding of this heart failure scenario. The mechanisms, time course (both in experimental models and clinical experiences) and predictors of reverse-remodelling after arrhythmia suppression are described. The novel experience hereby presented may aid everyday clinical practice, promoting a new paradigm involving more complex, multi-level and multi-modality evaluation and possible earlier intervention at least in some patient subsets.

The effects of catheter ablation of outflow tract premature ventricular complexes on atrial electromechanical delay

BACKGROUND

Consistent data from several studies have shown that catheter ablation of frequent premature ventricular complexes (PVCs) results in substantial improvement in left ventricular ejection fraction (LVEF), left ventricular diastolic function, and left atrial volume and mechanics. However, the effects of catheter ablation of PVCs on atrial electromechanical properties have not been documented yet.

AIMS

In the present study, we investigated the short-term effects of radiofrequency catheter ablation (RFCA) of outflow tract PVCs on atrial electromechanical delay (EMD).

METHODS

A total of 71 subjects with idiopathic outflow tract PVCs who underwent RFCA were included. Interatrial and intra-atrial EMDs were measured by tissue Doppler imaging before and 3 months after catheter ablation.

RESULTS

The study population was divided into normal ejection fraction (EF) and low-EF subgroups according to their LVEF. In all study groups, substantial improvement was found in lateral electromechanical coupling time (PA), septal PA, right ventricular PA, interatrial EMD, left-sided intra-atrial EMD, and right-sided intra-atrial EMD. No treatment heterogeneity was observed when comparing low-EF and normal-EF subgroups with respect to atrial EMDs (interatrial EMD, interaction p = .29; left-sided intra-atrial EMD, interaction p = .13; right-sided intra-atrial EMD, interaction p = .88).

CONCLUSION

RFCA of outflow tract PVC has a favorable early effect on intra- and inter-atrial EMDs irrespective of preprocedural LVEF.

Impaired left ventricular global longitudinal strain improves with radiofrequency catheter ablation in patients with PVC-induced cardiomyopathy

BACKGROUND

In our study, we aimed to evaluate left ventricular global longitudinal strain (LV-GLS) value in patients with premature ventricular contractions (PVCs) and reduced LV ejection fraction (LVEF) and to determine the effect of radiofrequency catheter ablation (RFA) procedure on LV-GLS.

METHODS

In this cross-sectional study, 150 patients who underwent three-dimensional RFA with the diagnosis of PVCs were included. LV-GLS was measured with strain echocardiography in all patients before RFA and in the sixth-month control. Patients included in the study were grouped as LVEF <50% (Group I) and LVEF ≥50% (Group II) according to baseline LVEF, and patients within Group I were grouped as LVEF <50% (Group A) and LVEF ≥50% (Group B) according to the sixth-month LVEF.

RESULTS

There were 39 patients (26%) with baseline LVEF <50%. In 14 (36%) of these patients, LVEF <50% was observed to continue during the sixth-month controls. Both the baseline and sixth-month LV-GLS values were significantly lower in Group I patients (<0.01). RFA treatment significantly increased both LVEF and LV-GLS (<0.01). It was found that age, N-terminal pro-brain natriuretic peptide, LV diameters, and baseline LVEF were higher, and baseline LV-GLS level was lower in Group A patients (P < .01). Baseline LVEF and LV-GLS values were found to independently determine the patients in Group A (P < .01). In receiver operator characteristic analysis, when the limit value is accepted as 40% for baseline LVEF and 18% for baseline LV-GLS, it can determine Group A with acceptable sensitivity and specificity.

CONCLUSIONS

LV-GLS decreases significantly in patients with reduced LVEF and PVCs. In these patients, RFA treatment significantly increases both LVEF and LV-GLS.